Jman13
Offline
Upload & Sell: On
|
 Re: Official: Fujifilm GFX 50S Medium Format Announced! | |
GMPhotography wrote:
Dan diffraction hits sooner on a larger sensor than it does on a smaller system. . Using f22 on a large sensor is like death even f16 is bad. You actually have to shoot more wide open than 35 FF . Why I brought up tilt is very popular to MF folks as we need it far sooner at like F8 . Avoiding diffraction is easier with 35
gdanmitchell wrote:
Fred Miranda wrote:
Yes, the very expensive 53 x 40mm sensor used in bigger digital MF cameras is indeed larger but...
it\'s now easy to dismiss MF 44 x 33mm. Just call it \"mini\". 
I think going from APS-C to Full Frame is very substantial.
Full frame to MF (44 x 33) is not much different and the same argument can be made.
Fred, I don\'t mean it in a dismissive way at all — I just mean it as an easily understood way to express the difference.
It might be possible for some to think I\'m dissing the mini MF format itself, but this not the case at all. Note that my particular perspective on this camera is directly tied to my own use case, and other will certainly feel differently about it.
In fact, I\'m not quite ruling it out for me in the longer term. Two things (given what I can do with my current FF system in my photography) could sway me:
1. The availability of more lenses that I need for the purposes that make mini MF interesting to me. This could happen in the same way it did with the X-trans system, where Fujifilm has filled out the lens options quite nicely.
2. Higher sensor resolution that what I can achieve with my full frame system. (Yes, with the same roughly 50MP sensor resolution the larger sensor can produce somewhat higher system resolution, but that is already quite high with FF.)
So, no, I think \"mini MF\" is a good thing!
GMPhotography wrote:
gdanmitchell wrote:
One potential advantage of a larger format (though everyone needs to keep in mind that \"mini MF\" 33mm x 44mm is not that much larger than full frame!) is that it can provide a greater range of usage aperture options and potentially more control of DOF. (Note that \"more control of\" is not the same as \"more.\")
While acknowledging that in many cases the maximum aperture available may be smaller with larger format system lenses, one can use smaller apertures with less effect from diffraction blur in the final print at a given size. So while you might avoid using, say, f/22 on a full frame system in most cases, you could use it with less concern on a mini MF system.
(Many reading this will already understand, but others should be cautious about extending this to be equivalent to things said about \"real\" medium format systems, which typically were larger-to-much-larger than mini MF.)
Dan
Matt Grum wrote:
Steve Spencer wrote:
Matt if you shoot portraits at an aspect ration of 4 to 3 or squarer (such as 4 to 5 for an 8 X 10 or 16 X 20), then the crop factor for FF 35mm compared to this mini MF is 1.38X. So the Fuji 110 f/2 will be very similar in effective focal length and depth of field to an 80mm f/1.4 lens on 35mm FF. The FF 35mm will still have the slightest advantage, but it may well be within the rounding range of how aperture is reported, and sure there are a couple 85mm f/1.2 lenses for FF 35mm, but the Fuji 110 for portraits will be very very close in creating depth of field for portraits to what you can get on FF 35mm at least if you crop to most typical framing ratios for portraits.
The point I was addressing was that \"MF offers shallower depth of field\" - being close (but still worse) at exactly one focal length, whilst not getting anywhere near at other lengths such as 50mm f/0.95, 105mm f/1.4 doesn\'t really equate to \"better\" in my book.
I\'m not saying the system is inadequate for portraits, far from it, it\'s just not \"better\" when \"better\" is defined as shallower depth of field.
Sorry Dan that is wrong . It\'s going to start diffracting at F8. I owned 5 Phase backs with tech cams and DSLR bodies as well. Diffraction is a big issue . tilt and shift lens mounts or tilt in body are huge pluses to avoid diffraction and gain DOF without stopping down. Focus stacking is another technique used very often. I had a tech cam where the lens mount itself would do tilt and shift, Cambo to be exact. Arca also has it in their lens mounting plate. FYI phase one 80 Mpx back actually starts diffracting at f5.6 given the pixel pitch and tech lenses. Hard to spot but it starts there.
DOF has less effect on this size back compared to the full frame backs.
The aperture at which it \"starts diffracting\" is not the point.
The point is that whatever aperture you calculate you to produce \'too much diffraction\' on full frame, this point will occur at a smaller aperture on a larger system. If you feel that it is f/5.6 on FF, it might be f8 on mini MF. If you are comfortable with f/16 on FF, you are likely to be equally comfortable with f/22 on mini MF.
Dan
That doesn\'t make any sense. The diffraction effect is a physical property of photons moving through a small opening. That doesn\'t change regardless of what sensor is behind it. The \'point\' light source becomes diffused through the scattering of photons through a small opening, and the smaller opening relative to the focal length (f-stop) is what determines how large that airy disk is. The point at which this becomes visible at 100% will depend on the f-stop and the size of the pixel microlens...if the airy disk covers more than one photosite, you will see softening from diffraction. If it covers a bit of adjacent ones, you see a little, if it covers multiple photosites you see major softening. Based on the physics, the aperture at which diffraction softening depends mostly on pixel pitch, then, rather than format per se, but only when viewing files at 100%.
So, a 50 megapixel FF sensor and this sensor have difference in pixel size of around 1.27 (4.14 microns vs. 5.3 microns.) Therefore, you\'d expect diffraction at the PIXEL level (viewing at 100%) to show identical quality at around 2/3 stop smaller aperture (so f/14 on the Fuji would have identical pixel level diffraction as f/11 on the Canon).
At the pixel level, a 100 MP mini MF sensor would show diffraction much earlier than on this Fuji due to the smaller pixel pitch, but the final effect on the image would be roughly the same, as the size of the airy disk on to the sensor would be the same, it would just use more pixels on the denser sensor....so you wouldn\'t get the full resolution advantage when you\'re diffraction limited. That\'s what makes something diffraction limited.
To the point you are making, however, f/22 will look pretty soft on this sensor at 100%. f/22 looks soft at 100% on my A7 II, and that has a pixel size of 5.97 microns, so larger than the Fuji. So, at f/22 diffraction will look slightly worse at 100% with this Fuji vs. my A7 II. Due to the higher resolution due to the larger area, the final image will look a fair bit better.
This is a great guide to diffraction, including interactive examples using many cameras, as well as theoretical calculations based on format size. http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm
|
